What an amazing coin, Ernie! These small silver denominations were issued by the old German state of Silesia-Liegnitz-Brieg, written on the coin as 'SIL', 'LIGNIC', and 'BREGENS', respectively.
The person on the coin is Christian, Duke of Brieg, who lived from 1618 to 1672. Christian was a noble of the House of Piast - a family which had earlier ruled Poland, and can be traced back to the mid-10th century.
The coin in our picture is from Beast Coins, a seller in Florida that specializes in rare and exotic coins. His coin is 21-22 millimeters in diameter, and weighs 1.59 grams. It is being sold for $65, which is a great price for such a coin, which would grade just above 'well preserved'.
The catalogs report the same values for all three dates of these coins:
worn: $10 US dollars approximate catalog value
average circulated: $30
well preserved: $70
fully preserved: $150
A coin that is bent, scratched or poorly cleaned will be worth less. Your slightly concave coin, Ernie, is probably not damaged. These coins were produced with a rolled flan, which means that hot piece of silver was rolled with the blacksmithing equivalent of a rolling pin. Sometimes, this would produce a slightly concave flan as the metal cooled down, and the tension would warp the coin slightly. This is not a perfect example of a coin, but it should not reduce the value.
As always, refer to our 'Important Terminology' page in order to properly understand what the term 'catalog value' means.